Nail lacquers represent new drug form specifically designed to treat infected nail plate. They are complex organic solutions with specific assaying problems due to the high content of the polymer and plasticizer. Furthermore, there is a lack of assaying methods of active substances from this type of formulations in scientific literature. We developed derivative UV-spectrophotometric method for determination of fluconazole content in antifungal nail lacquer formulations. The method was validated for specificity, linearity, precision (repeatability), intermediate precision and accuracy (recovery). The method is specific, linear in the range of 99.53 - 497.65 μg/ml, precise and showed good recovery (98.79% - 101.77% from all six developed formulations). Besides, it is inexpensive, simple and nontoxic, i.e. ecologically acceptable. This method can be used for assaying fluconazole from this type of formulations.
Onychomycoses, fungal nail infections, are responsible for 50% of all nail disorders affecting up to 18% of general population in some countries [1]. [...]
For the majority of the pharmaceutical dosage forms, the substances that are used maintain solid state under the standard storage conditions, i.e. powders. The interactions of pharmaceutical powders (active ingredient(s) and excipients) with liquids and vapors (particularly aqueous solutions and their vapors) occur almost always during the production process. From the physical point of view, the interactions among individual components may differ from the expected because chemically identical substances obtained from different producers vary very much. These differences influence either the production process and/or the pharmaceutical form properties. In order to overcome these problems it is necessary to establish a control over the physico-chemical properties of the used materials. The aim of this work was to determine physico-chemical properties of three powder clindamycin phosphate samples (labeled as sample S(1), S(2) and S(3)) acquired through different suppliers. All the analysis were made for the purpose of establishing possible differences among the tested samples that showed variable physical stability in the solution: recrystallization of the S(3) sample in the aqueous solution has been established during storage under standard conditions. On the basis of the obtained data it was possible to recognize the differences among the tested clindamycin phosphate samples and to explain the anomalous behavior of one sample. The surface free energy components for the investigated clindamycin phosphate samples were determined using Wu and Good- van Oss method. The investigated clindamycin phosphate samples exhibit certain differences in surface free energy values as well as in surface morphology and thermal behavior. Comparison of alpha + and alpha - values leads to the conclusion that all three clindamycin phosphate samples perform as monopolar, more electron acceptors, i.e. Lewis acids. However, an important difference exists between samples S(1) and S(2) on one and S(3) on the other side. Sample S(3) exhibits stronger acidic behavior, what could be connected with its recrystallization during the storage. The samples S(1), S(2) and S(3) have different melting points e.g. "onset" temperatures. When the melting points move towards 200 (o ) C, the width of the "onset" temperature peak is especially important. In the case of wider peak, the potential for recrystallization seems to be higher. According to the stated, the sample S1 would be the "sample of choice" for the formulation of the stable pharmaceutical dosage form and has not shown any recrystallization tendencies during the storage period.
Sustained-release theophylline pellets formulation for once-daily evening administration significantly improved patients compliance and adjusted serum levels profile of the drug. The patients conversion from i.v. to p.o. therapy is one of the most critical steps in the treatment of asthma according to its chronopathophysiological character. In our study we have examined safety and efficiency of this conversion in twelve hospitalised asthmatic patients who were given the new sustained-release theophylline pellets formulation for once-daily evening administration. The lung function parameters (FEV1, VC, RV, and Rt) and serum theophylline concentrations were monitored. So, the values obtained for the last day of i.v. therapy and the fifth day of p.o. therapy were compared. We found that 75% of the patients had no change or improved lung function on the conversion. Our results indicate that this conversion from i.v. to p.o. theophylline therapy is safe and could be efficacious. Also, the maximum theophylline serum levels could safely be predicted by measuring only one serum concentration in p.o. therapy with sustained-release theophylline pellets formulation for once-daily evening administration.
In recent years, drug release/dissolution from solid dosage forms has been the subject of intense and profitable scientific developments. Whenever a new solid dosage form is developed or produced, it is necessary to ensure that drug dissolution occurs in an appropriate manner. The pharmaceutical industry and the registration authorities do focus, nowadays, on drug dissolution studies. The quantitative analysis of the values obtained in dissolution/release tests is easier when mathematical formulas that express the dissolution results as a function of some of the dosage forms characteristics are used. This work discusses the analysis of data obtained for dissolution profiles under different media pH conditions using mathematical methods of analysis described by Moore and Flanner. These authors have described difference factor (f1) and similarity factor (f2), which can be used to characterise drug dissolution/release profiles. In this work we have used these formulas for evaluation of dissolution profiles of the conventional tablets in different pH of dissolution medium (range of physiological variations).
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